1. Field of the Invention
The invention relates to the spiral wire binding of stacks of sheets, particularly pads or booklets of smaller sizes, such as 6 inch by 9 inch steno pads or similar books.
2. Description of the Prior Art
An example of a coil binding machine used for this purpose is shown in my U.S. Pat. No. 3,924,664 and the patents referred to therein. In these machines, groups of sheets are fed to a perforating mechanism such as a punching unit and from there to a rotating carriage at which each pad is fed to successive stations. At one station the outwardly positioned holes are aligned, at another station a spiral wire binder is fed therethrough and severed from the supply, and at a third station the outer ends of the spiral are trim-cut and bent inwardly.
When a smaller size pads are used in this rotating unit, it is possible for such a machine to bind more booklets per unit of time because the time for feeding each coil is less than for longer edges. However, the speed of the operator who manually feeds the booklets at the beginning of the line remains the same regardless of the size of the book. The rotating unit is thus not operating at its potential capacity.
The conventional trim-cutting and bending apparatus, as shown in the above-mentioned prior art, comprises an assembly having a fixed cutter member which engages the spiral end and a cutter blade operated by a cam having a diagonal slot. Because of the bulky nature of this prior trim-cutting and bending assembly, it is possible to use such a construction to trim-cut and bend two closely spaced spiral binder ends.